1. Field of the Invention
The present invention relates to postage meters and, in particular, to microcomputerized, miniature postage meters which may be held in and operated by hand, are completely portable, and may be stored in any one of a number of small spaces such as a pocket, purse, or briefcase.
Postage meters are now widely used by commercial and industrial businesses to selectively print postage indicia on documents such as envelopes, labels, and the like. Managers of these businesses, which frequently generate medium to large volumes of mail, have found that meters are capable of handling postage far more rapidly, economically, and conveniently, than manual operators who individually moisten and position previously printed postage stamps on mailing documents. Furthermore, printed postage is attractive as well as impressive to the recipient of the mail on which it appears.
However, individuals who use postal services relatively infrequently compared to business enterprises have been unable to avail themselves of the advantages of postage meters for a number of reasons. Primarily, the use of presently known meters is only economically feasible when relatively large volumes of postage are printed. Furthermore, since these meters are ordinarily large and cumbersome, they are usually mounted for operating at a fixed location. Therefore, they are inconvenient for use by a person who is accustomed to carrying postage, in the form of previously printed stamps, with him.
2. Description of the Prior Art
Postage meters which are now generally available are specifically designed for institutional use by entities having need for large volumes of postage. Thus, as noted, these meters are usually large and are mounted at a fixed location. Typically, they employ a complex mechanical printing device comprised of either a rotatably mounted printing die plate, operated to rotate in synchronism with linearly moving documents, or a fixed printing die plate against which documents are mechanically pressed, to imprint the documents with the desired postage indicia.
A postage meter construction has been proposed in U.S. Pat. No. 3,869,986 (Hubbard), assigned to the assignee of the present invention, which employs a rotatably mounted die plate to print fixed postage information, such as the postage meter registration number, and an ink jet printing device to print variable postage information such as the date and postage amount.
Still more sophisticated postage meters, which nevertheless include mechanical postage printing apparatus, but which employ a microcomputer set to perform control and data processing functions, are disclosed in copending U.S. patent applications, Ser. Nos. 536,248 filed, Dec. 23, 1974 and 568,460 filed Apr. 16, 1975, and U.S. Pat. Nos. 3,978,457 and 4,097,923 which, respectively, issued from said applications, all assigned to the assignee of the present invention. However, none of these postage meters may be conveniently used by an individual who generates relatively low volumes of mail yet who requires immediate access to postage regardless of the time or place.